Biology subjects

Zhang, C. Y.

Publications and source records attributed to Zhang, C. Y..

12 recordsLinked to original sources

bioRxiv2026

Recognition of the centromere-binding protein Ndc10 by Scm3HJURP directs Cse4CENP-A deposition at native centromeres

Kinetochores connect centromeres to spindle microtubules, ensuring accurate chromosome segregation. Kinetochore assembly at centromeres depends on deposition of CENP-A, a histone H3 variant. Despite considerable progress, how CENP-A is specifically assembled on native centromeres remains an open question. Centromere-specific assembly of CENP-A occurs spontaneously in a cell-free extract system from the yeast Saccharomyces cerevisiae, but with low efficiency, suggesting that one or more factors are limiting. Here, we show Scm3HJURP, a specific chaperone for the centromeric histone Cse4CENP-A, is one such limiting component. The addition of a complex of Scm3, Cse4 and histone H4 strongly stimulates Cse4 assembly in a centromeric DNA sequence- and dose-dependent manner; in addition, improvements in both Cse4 and kinetochore assembly were more prominent in mitotic versus interphase (G1) extracts. Using the complemented cell-free reconstitution system, we show that distinct Scm3 interfaces with Cse4 and with the Ndc10 subunit of the yeast centromere DNA sequence-recognizing CBF3 complex are essential for centromere-specific Cse4 assembly and cell viability. Thus, recognition of Ndc10 directs Scm3-dependent and locus-specific centromeric histone deposition.

biochemistry↗

bioRxiv2026

Caffeinated Coli: Inspiring the Next Generation of Scientists through Synthetic Biology

The Caffeinated Coli Educational Module brings inquiry-driven learning to high schools, introducing students to scientific research, synthetic biology, and genetic engineering. The module focuses on the exploration of a genetically engineered strain of E. coli modified to grow exclusively on caffeine and, as such, can be used as a measurement device to determine the amount of caffeine in a liquid or beverage. Students conduct two bioassay experiments using these bacteria. During this process, they learn to create cultures and then measure bacterial growth followed by calculating the caffeine concentrations of unknown samples using their own data. This flexible module contains five weeks of original lectures and student learning materials that follow Next Generation Science Standards (NGSS), allowing the content to be adapted for basic, intermediate, or advanced biology courses. Upon completion of the module, students and teachers expressed that the most memorable aspects of the module include collaboration with peers, hands-on learning of content, and the opportunity to interact with the professor/mentors through office hours. Already implemented in 8 Texas high schools over the past two academic years, our module inspires STEM learning while bringing 21st century biology research to new audiences.

scientific communication and education↗

bioRxiv2026

Nonanticoagulated Heparin Derivatives Mediate Goblet Cell Differentiation to Restore the Mucosal Barrier for Ulcerative Colitis Therapy

Epithelial mucus barrier dysfunction is a pathological hallmark of ulcerative colitis (UC), yet current clinical therapeutic strategies primarily suppress inflammation, lacking reliable approaches for restoration of the mucosal layer. Here, through a systematic screen of our established library of deanticoagulated heparins, we identified NALHP, a non-anticoagulant low-molecular-weight heparin derivative, and its representative fraction S6 as orally active epithelial repair-promoting glycans. NALHP/S6 restored crypt architecture, mucus production and epithelial barrier integrity in experimental colitis. In UC patient-derived colonic organoids, NALHP/S6 reduced aberrant stem/proliferative programs while promoting secretory, absorptive and junctional maturation. Single-cell transcriptomics and temporal validation identified a transient repair-secretory transitional state (RSTS) positioned between classical Wnt-associated stemness and mature barrier-forming epithelial states. Transcriptomic analysis revealed coordinated attenuation of Wnt and Notch signaling, whereas pharmacological reactivation of these pathways opposed NALHP/S6-induced epithelial state progression. These findings define mucosal repair as a regulated epithelial-state transition and identify NALHP/S6 as glycan-based modulators capable of restoring this progression in UC epithelium.

pathology↗

bioRxiv2025

Induced ubiquitination bypasses canonical ERAD to drive ER protein degradation

Heterobifunctional proteolysis-targeting chimeras (PROTACs) have emerged as a powerful strategy to degrade disease-relevant proteins, enabling targeting of previously "undruggable" proteins. Current degrader molecules primarily target cytosolic substrates, yet nearly one-third of the proteome resides in or transits the endoplasmic reticulum (ER), including receptors, secreted factors, and biosynthetic enzymes with high therapeutic relevance. Whether ER-localized proteins can be broadly targeted for induced degradation remains an open question. To address this gap, we employed a panel of fluorescent reporter cell lines and used the dTAG chemical-genetic system to recruit cytosolic E3 ligases. While lumenal substrates segregated from the cytosol were resistant to degradation, recruitment of cytosolic ligases effectively degraded ER membrane proteins across multiple topologies and with post-translational modifications. CRISPR genetic screens revealed that the induced degradation required the expected cullin RING ligase complexes but surprisingly bypassed ER-associated degradation (ERAD) machinery, with the exception of the AAA ATPase VCP. Mechanistic studies demonstrated that substrate ubiquitination was essential for VCP binding, and cleavage of ubiquitin chains released VCP, suggesting a model in which VCP directly extracts substrates independent of a dislocation apparatus. Extending this strategy to an endogenous substrate, we synthesized an HMGCR ERAD-TAC by linking atorvastatin to a cereblon E3 ligase recruiter and found that HMGCR degradation was likewise VCP-dependent. Together, these findings demonstrate that ER membrane proteins are generally susceptible to induced degradation via cytosolic ligase recruitment, uncovering a VCP-centered mechanism that operates independently of membrane-embedded ERAD machinery. This work establishes foundational principles for extending targeted protein degradation to the early secretory pathway. SIGNIFICANCE STATEMENTTargeted protein degradation has transformed drug discovery. Nearly one-third of the proteome reside in or transit the endoplasmic reticulum (ER), a compartment rich in therapeutically relevant but structurally complex targets. Whether these ER proteins can be broadly degraded using PROTACs has remained unknown. Here, we define the minimal requirements for degrading ER membrane proteins by recruiting cytosolic E3 ligases. Using chemical-genetic tools, genetic screens, and a statin-based degrader, we show that ubiquitination engages the VCP extraction machinery, enabling degradation of diverse ER membrane proteins independent of canonical ER-associated degradation components. These findings reveal a ubiquitin-driven route for membrane protein turnover, expand the landscape of druggable ER proteins, and establish principles for designing degraders operating in the early secretory pathway.

cell biology↗

bioRxiv2025

Graded Notch Signaling Functions as a Rheostat of Lineage Plasticity and Therapy Resistance in Prostate Cancer

Resistance to androgen receptor (AR)-targeted therapies such as enzalutamide in castration-resistant prostate cancer (CRPC) often arises through lineage plasticity, yet the molecular mechanisms that define this process remain incompletely understood. While previous studies reported that Notch1 and Notch2 exert distinct and sometimes opposing effects in prostate cancer differentiation, the integrated role of Notch pathway activity has not been systematically explored. Here, we identify Notch signaling as a graded Rheostat that governs prostate cancer cell fate transitions. Integrative transcriptomic and functional analyses revealed that intermediate Notch activity maintains a stem-like progenitor state, whereas reduced or elevated signaling drives divergent differentiation trajectories toward luminal or neuroendocrine lineages, respectively. During CRPC progression and enzalutamide resistance, Notch signaling becomes dynamically rewired, peaking in progenitor-like populations that sustain plasticity and survival. Both CRISPR-mediated knockout and pharmacologic inhibition of Notch signaling depleted these progenitor cells and restored enzalutamide sensitivity. These findings demonstrate that the level, rather than the binary presence, of Notch signaling dictates lineage directionality and therapeutic response in CRPC, establishing it as a tunable and actionable driver of resistance.

cancer biology↗

bioRxiv2025

RUNX1T1-HDAC Reprogramming of the HOX Code Signaling Drives a Targetable Pan-Cancer Lineage Plasticity

Cancer remains a leading cause of death worldwide, with lineage plasticity emerging as a hallmark that drives therapy resistance and tumor progression by enabling cancer cells to alter identity and evade targeted therapies. Although genomic and transcriptomic aberrations correlate with lineage plasticity, the absence of pan-cancer markers to rapidly identify plastic subtypes has limited predictive utility. Homeobox (HOX) genes encode transcription factors that define tissue identity through distinct expression patterns, or HOX codes, in specific lineages. By analyzing multi-omics data, including 39 HOX genes from over 80,000 RNA-seq samples across 114 cancer types, we discovered that HOX code expression robustly represents cancer cell lineages and reveals multiple previously unrecognized lineage-plastic subtypes in prostate cancer, lung cancer, and acute myeloid leukemia (AML), each displaying altered HOX patterns compared to non-plastic subtypes. Differential analysis further identified RUNX1T1 as a novel and consistent marker of plasticity, elevated across all three cancer types and correlating with HOX code and lineage-plastic marker genes. We validated these correlations in bulk and single-cell RNA-seq from extensive preclinical and clinical cohorts and provided direct functional evidence that RUNX1T1 is required for lineage-plastic programs in prostate cancer. Using AI-based modeling, we identified NCOR/HDAC as RUNX1T1 binding partners forming a co-repressor complex that regulates HOX codes and plasticity. Finally, pharmacologic HDAC inhibition selectively suppressed the growth of plastic cells, revealing a novel therapeutic vulnerability. These findings establish ectopic RUNX1T1 as a pan-cancer biomarker and critical mediator of lineage plasticity and identify the RUNX1T1-HDAC complex as a druggable target.

cancer biology↗

bioRxiv2024

Orally surface engineered probiotic system for ulcerative colitis therapy via modulating gut microbiota and immune homeostasis

Oral probiotics have emerged as a promising therapeutical strategy for effectively managing ulcerative colitis (UC) in the world. The existing researches successfully preserve probiotic viability in the upper gastrointestinal tract, but they fall short in achieving precise release profile and effective colonization of probiotics at the site of colitis in colon as well as the understanding of therapeutic mechanism with suboptimal efficacy. This constraint poses a significant barrier to rational design and effective development of oral probiotic system. Here, we fabricate an orally layered-by-layered probiotic (Escherichia coli Nissle 1917, EcN) system (so-called CML@EcN) based on carboxymethyl modified lignin (CML) which can significantly protect EcN in gastric and small intestinal microenvironment and efficiently control release EcN in colon. Interestingly, the release and proliferation process of EcN in the colon are detected and can be modeled as a plug-flow mode. We derive a mathematical expression that highly matches the experimental results, providing a theoretical basis for quantitatively calculation of the release process. Furthermore, CML@EcN significantly alleviates symptoms in dextran sulfate sodium (DSS)-induced UC mice by modulating the multiple organ immune disorder and gut microbiota (GM)/metabolites profile as well as reconstructing the colon barrier. Importantly, we explore the mechanism of immune homeostasis regulation via metabolism from GM. Moreover, the CML armour is excreted and would not influence the process. This work not only reports a novel oral therapeutic for UC treatment with high efficacy as well as the exploration of mechanism between GM and immune homeostasis, but also provides a general approach to engineer probiotics for oral administration.

microbiology↗

bioRxiv2024

Concatemer Assisted Stoichiometry Analysis (CASA): a targeted mass spectrometry method for protein quantification

Large multi-protein machines are central to multiple biological processes. However, stoichiometric determination of protein complex subunits in their native states presents a significant challenge. This study addresses the limitations of current tools in accuracy and precision by introducing concatemer-assisted stoichiometry analysis (CASA). CASA leverages stable isotope-labeled concatemers and liquid chromatography parallel reaction monitoring mass spectrometry (LC-PRM-MS) to achieve robust quantification of proteins with sub-femtomole sensitivity. As a proof-of-concept, CASA was applied to study budding yeast kinetochores. Stoichiometries were determined for ex vivo reconstituted kinetochore components, including the canonical H3 nucleosomes, centromeric (Cse4CENP-A) nucleosomes, centromere proximal factors (Cbf1 and CBF3 complex), inner kinetochore proteins (Mif2CENP-C, Ctf19CCAN complex), and outer kinetochore proteins (KMN network). Absolute quantification by CASA revealed Cse4CENP-A as a cell-cycle controlled limiting factor for kinetochore assembly. These findings demonstrate that CASA is applicable for stoichiometry analysis of multi-protein assemblies. SummaryThis study presents Concatemer-Assisted Stoichiometry Analysis (CASA) to address a common challenge in cell biological research: quantifying the number of each protein subunit in a native protein complex.

molecular biology↗

bioRxiv2024

Functional metagenomics reveals an alternative, broad-specificity pathway for metabolism of carbohydrates in human gut commensal bacteria

The vast majority of the glycosidases characterised so far follow one of the variations of the "Koshland" mechanisms to hydrolyse glycosidic bonds. Herein we describe a large-scale screen of a human gut microbiome metagenomic library using an assay that selectively identifies non-Koshland glycosidase activities. This screen led to identification of a commonly occurring cluster of enzymes with unprecedentedly broad substrate specificities that is thoroughly characterised, mechanistically and structurally. Not only do these enzymes break glycosidic linkages of both and {beta} stereochemistry and multiple connectivities, but also substrates that are not cleaved by standard glycosidases. These include thioglycosides such as glucosinolates and pseudo-glycosidic bonds of pharmaceuticals such as acarbose. This is achieved via a distinct mechanism of hydrolysis that involves stepwise oxidation, elimination and hydration steps, each catalysed by enzyme modules that are in many cases interchangeable between organisms and substrate classes. These appear to constitute a substantial alternative pathway for glycan degradation.

biochemistry↗

bioRxiv2024

"Hitting Two Birds with One Stone" Design of Intestinal Integrin-Targeting and Redox Homeostasis-Regulating Oral Nanotherapy for Ulcerative Colitis

Designing highly efficient orally administrated nanotherapeutics with specific inflammatory site-targeting functions in the gastrointestinal (GI) tract for ulcerative colitis (UC) management is a significant challenge. Straightforward and adaptable modular multifunctional nanotherapeutics represent groundbreaking advancements and are crucial to promoting broad application in both academic research and clinical practice. In this study, we focused on exploring a specific targeting modular and functional oral nanotherapy, serving as "one stone", for the directed localization of inflammation and the regulation of redox homeostasis, thereby achieving effects against "two birds" for UC treatment. The designed nanotherapeutic agent OPNs@LMWH, which has a core-shell structure composed of oxidation-sensitive {varepsilon}-polylysine nanoparticles (OPNs) in the core and low-molecular-weight heparin (LMWH) in the shell, exhibited specific active targeting effects and therapeutic efficacy simultaneously. We qualitatively and quantificationally confirmed that OPNs@LMWH possessed high integrin M-mediated immune cellular uptake efficiency and preferentially accumulated in inflamed lesions. Compared with bare OPNs, OPNs@LMWH exhibited enhanced intracellular reactive oxygen species (ROS) scavenging and anti-inflammatory effects. After oral administration of OPNs@LMWH to mice with dextran sulfate sodium (DSS)-induced colitis, robust resilience was observed. OPNs@LMWH effectively ameliorated oxidative stress and inhibited the activation of inflammation-associated signalling pathways while simultaneously bolstering the protective mechanisms of the colonic epithelium. Overall, these findings underscore the compelling dual functionalities of OPNs@LMWH, which enable effective oral delivery to inflamed sites, thereby facilitating precise UC management.

bioengineering↗

bioRxiv2023

Universal protection against SARS-CoV-2 viruses by multivalent mRNA vaccine in mice

The continual emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants challenges available SARS-CoV-2 vaccines for adequate control of outbreaks. Currently, universal vaccines capable of obviating the need for exact strain matching between mRNA vaccines and circulating viruses are absent. In this study, we designed, manufactured, and evaluated a nucleoside-modified lipid nanoparticle mRNA vaccine, aimed for offering broad-spectrum protection against recent SARS-CoV-2 variants. Additionally, the protection efficiency of monovalent, bivalent, quadrivalent, and XBB.1.5 mRNA vaccines was compared with the proposed universal vaccine. The neutralizing antibody activity against wuhan-1, BA.4/5, XBB.1.5, B.1.1.529, BQ.1.1, EG.5.1 and JN.1 was assessed using enzyme-linked immunosorbent assay, rapid fiber-optic biolayer interferometry-based biosensor, and pseudovirus neutralization test. Our results reveal that the proposed multivalent vaccine affords comprehensive protection against previously circulating, current and previously unidentified SARS-CoV-2 strains.

immunology↗

bioRxiv2019

Inhibitory effect of Bacillus subtilis WL-2 and its IturinA lipopeptides against Phytophthora infestans

Potato late blight triggered by Phytophthora infestans ((Mont.) de Bary) represents a great food security threat worldwide and is difficult to control. Currently, Bacillus spp. have been considered biocontrol agents to control many fungal diseases. Here, Bacillus subtilis WL-2 was selected as the antifungal strain with the most potential against P. infestans mycelium growth. Additionally, the functional metabolites extracted from WL-2 were identified as IturinA-family cyclic lipopeptides (CLPs) via high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). Analyses using scanning and transmission electron microscopy (SEM and TEM) revealed that IturinA caused a change in the mycelial surface and damage to the internal cell structure, including cell membrane disruption and irregular organelle formation. Moreover, propidium iodide staining and nucleic acid and protein release were detected to clarify the cell membrane damage caused by IturinA. Additionally, IturinA triggered reactive oxygen species (ROS) generation and malondialdehyde (MDA) production. Mitochondrial membrane potential (MMP), mitochondrial respiratory chain complexes activity (MRCCA), respiratory control rate (RCR), and oxidative phosphorylation efficiency (P/O) assays indicated that P. infestans mitochondria affected by IturinA were so seriously damaged that the MMP and MRCCA declined remarkably and that mitochondrial ATP production ability was weakened. Therefore, IturinA induces cell membrane damage, oxidative stress, and dysfunction of mitochondria, resulting in P. infestans hyphal cell death. As such, the results highlight that B. subtilis WL-2 and IturinA have great potential as candidates for inhibiting P. infestans mycelium growth and controlling potato late blight.\n\nIMPORTANCEPotato (Solanum tuberosum L.) is the fourth most common global food crop, and its planting area and yield increase yearly. Notably, in 2015, China initiated a potato staple food conversion strategy, and by 2020, approximately 50% of potatoes will be consumed as a staple food. The plant pathogen fungus Phytophthora infestans ((Mont.) de Bary) is the culprit of potato late blight; however, biological agents rather than chemicals are highly necessary to control this threatening disease. In this study, we discovered an antifungal substance, IturinA, a lipopeptide produced by Bacillus subtilis WL-2. Moreover, our research revealed the actual mechanism of IturinA against P. infestans mycelium growth and clarified the potential of B. subtilis WL-2 and IturinA as a biocontrol agent against P. infestans mycelium growth as well as for controlling the development of late blight in potato cultivation.

microbiology↗